Thank you for the trip report, and great to hear that John of Diamondaire in Montana is going strong. Having someone committed to the type, both the Apache and the Aztec, will hopefully keep these twins going for some time.
Agree on the Janitrol heater in the nose – am not sure how the mixture was set on this heater, or if mixture is relevant, but it definitely would be gasping above, say F150.
Not many turbo charged Aztecs around in Europe, the old advertisements claimed 220KTAS at FL250 which makes a decent turn of speed for the original modified Clark Y airfoil.
John and the team are going strong – tons of new projects in the pipeline in Kalispell. Indeed, they are really committed to keeping the fleet in the air, I don’t think that I would have been able to operate 34kk without them.
Yes the heater issue is related to the mixture – it can’t be set (at least there is no control to do so, although you can lean it a little bit by partially turning the heater fuel knob, but it isn’t in the poh and it isn’t real science) so it can easily run too rich. FL130 is the maximum restart altitude in my experience, but if started low it will keep running at FL190 just fine. When it gasps it can become a nasty distraction. Maybe I should clean the spark plug, I don’t know. The unit has like 30 hours on it since overhaul (4 years ago..)
220KTAS is a bit enthusiastic, but it happily flies at 185KIAS and more importantly the useful load is a tad less than 1900lb – it makes a nice camper for the family while being decently easy to fly and landing relatively short. If you don’t care about fuel burn you can go faster but that fat wing has a lot of drag ..
